UV Index in Washington, United States

Last updated: August 1, 2025

Understanding the UV Index is crucial for residents of Washington, United States, where sunny days can unexpectedly lead to elevated UV exposure. Being aware of UV levels helps in preventing sunburn and safeguarding long-term skin health, allowing you to enjoy outdoor activities without the risk of damage. In Washington's Dfb climate, where seasonal variations can lead to fluctuating UV radiation, knowing when the UV Index peaks—like the notable highs around midday—can make all the difference in protecting your skin. Stay informed and stay safe under the sun!

Hourly UV Index in Washington

This hour-by-hour UV Index data paints a clear picture of sun intensity throughout the day. At 07:00 and 08:00, the UV Index remains low at just 1, making it safe for outdoor activities. However, as the clock ticks toward mid-morning, the value climbs to 2 by 09:00. The sun's power peaks between 12:00 and 14:00, with a striking 8 and 9 respectively, indicating a high risk of harm from unprotected sun exposure. By 15:00, the index begins to decrease, dipping to 8, and continues its descent through the late afternoon and evening, reaching 5 at 17:00 and down to 2 by 19:00. Remember, during those mid-day hours, proper sun protection is essential to enjoy the outdoors safely!

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	1	low	45 min
09:00	2	low	45 min
10:00	3	moderate	30 min
11:00	5	moderate	30 min
12:00	7	high	25 min
13:00	8	very high	15 min
14:00	8	very high	15 min
15:00	8	very high	15 min
16:00	6	high	25 min
17:00	4	moderate	30 min
18:00	3	moderate	30 min
19:00	1	low	45 min

Monthly UV Index Trends in Washington

Throughout the year, UV exposure varies significantly, with the highest risk occurring during the summer months of May through August. During this period, the UV Index reaches a peak of 9, classified as very high, with a minimal burn time of just 15 minutes. Conversely, the UV Index is at its lowest in January and December at 2, indicating a low risk of harm from sun exposure, allowing for a burn time of 45 minutes. April and September mark transitional months where the UV Index is high at 7, prompting caution with a burn time of 25 minutes. To protect against harmful UV radiation, it is crucial for both visitors and residents to take appropriate precautions, particularly from May to August, such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours.

Monthly Maximum UV Index for Washington, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Washington. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Washington, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Washington UV Index with Other United States Cities

The table above highlights how UV exposure in Washington compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Washington's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Washington	2	4	5	7	9	9	9	8	7	5	3	2
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5